Cast-iron pipe and process of making pipe



June 18, 1929. w, M|LLsPAUGH I 1,717,615

CAST IRON PIPE AND PROCESS OF MAKING PIPE Filed Feb. 19, 1926 Patented. June 18 1929 UNITED STATES WILLIAM H. MILLSPAUGH, OF SANDUSKY, OHIO, ASSIGN OR TO TILE MACHINERY COMPANY, OF

THE PAPER AND TEX- SANDUSKY, OHIO, A CORPORATION OI? OHIO.

CAST-IRON PIPE AND-PROCESS or MAKING PIPE.

Application filed February 19, i926. Serial No. 89,307.

This invention relates to cast iron pipe.

Ordinary blast furnace iron is unsuitable for use in centrifugally casting iron pipe since the impurities in the iron form a rough inner surface on the pipe and because of this roughness, the pipe is useless. Iron pipe cast on a sand liner also hasthis rough inner surface.

For this reason it is the practice to use a better grade of iron for casting pipe.

In carrying out this invention, however, the

roughness of the interior surface of the pipe is advantageous since it is utilized for holding a smooth lining of cement or other similar material.

This invention has for its salient object, therefore, to utilize the rough inner surface of a centrifugally cast pipe to facilitate the securing inthe pipe of a lining of'cement or like material.

Another object of the invention is to provide a process whereby centrifugally cast pipe can be made from ordinary blast furnace iron and can be provided with a smooth inner surface.

Another object is to provide a cast pipe formed of blast furnace or a similar grade of iron and having a smooth lining on 1ts inner surface.

Further objects of the invention will appear from the following specification taken in connection with the drawings, which form a part of this application, and in which Fig.1 is a longitudinal section of a pipe constructed in accordance with the invention;

and

Fig. 2 is a fragmentary sectional view showing on an enlarged scale the portion of the pipe wall.

In carrying out the invention, blast furnace iron is cast centrifugally into pipe anda suitable lining substance, such as cement, is introduced into the pipe preferably while the pipe.

is being rotated, and this lining substance coats the inside of the pipe filling in the rough surface and providing a smooth inner surface for the pipe. .7

The pipe when cast from blast furnace 11011 even although loose kish, graphite and other impurities are removed as much as poss1ble, will still have a rough and uneven inner surface. As is well known, pipe is cast centrifugally by pouring the molten metal into a rapidly rotating mold, the metal bemg suitable lining thrown out centrifugally against the mold and forming the molded product having the desired contour.

The moltenmetal is introduced into the mold by any other suitable manner and after the castmg has cooled, the next step in the process consists of introducing into the pipe preferably while it is rotating, cement or other material. The cement may be introduced into the rotating pipe by means of the dulnper trough or by spraying and because of the rough inner surface of the pipe, the cement will adhcre'thereto and fill in the interstices and uneven surface, thereby producing a smooth inner surface for the pipe. This is illustrated on anenlarged scale in Fig. 2 wherein the rough inner wall 10 of the pipe 11 has a coating 12 of cement or similar material.

If refined iron is used for making a centrifugally cast pipe, the inner surface of the pipe may be'too smooth to hold the'cement and for this reason, a coarser grade of iron, such as pig ironor iron chips, may be introduced into the machine before the inner surface of the pipe has fully solidified, thus anchorage for the cement.

From the foregoing description it will be evident that the rough inner surface of the pipe instead of being detrimental is really advantageous since the projections on the rough inner surface act as keying elements and hold or bind the lining to the pipe. Thus the process permits satisfactory pipe to be made from cheap grades of iron.

In other words, by means of the method above described, iron pipe may be formed from the coarser and cheaper grades of iron without being subject'to the disadvantages usually inherent in such pipe. Moreover, by providing a smooth lining for-the inner sur face of the pipe, it is possible to utilize blast furnace or the making pipe. 4

Although one specific embodiment of the invention has been particularly shown and described, it Will be understood that the invention is capable of modification and that changes in the construction and in'ther arrangement of the varlous cooperating parts may be made 'without cheaper grades of iron for means of a dumper trough or in providing a rough inner surface to form an departing from the spirit or scope of the invention, as expressed interstices and inwardly projecting parts, in the following claim. and a cement lining fillin said interstices What I claim is: and embedding said projecting parts, thereby A centrifugally cast pipe comprising a being rigidly lnterlock to the body, said lin 5 cylindrical body of iron containing a large ing having a smooth inner surface.

proportion of impurities distributed mainly In witness whereof, I have hereunto set on the inner portion of said body and formmy hand this 16th day of'Feb., 1926. ing a surface having irregularly distributed WILLIAM H. MILLSPAUGH, 

